1. Field of the Invention:
This invention relates to a camera permitting close-up photography and more particularly to a camera which can be switched over from a normal photographing mode to a close-up photographing mode.
2. Description of the Prior Art:
A camera arranged to permit close-up photography has an advantage in that a desired object can be photographed in a larger size. Generally, however, it is a drawback of the camera of this kind that the camera becomes very expensive as it necessitates use of a photo-taking lens which is capable of permitting focusing over a wide range from an infinity distance to the nearest distance. To solve this problem, Japanese Laid-Open Patent Application No. SHO 54-55836 has disclosed a camera in which the depth of field is increased by stopping down a diaphragm aperture to enable the lens to be focused on an object located at a nearer distance and the insufficiency of exposure to light due to the stopped down aperture is covered by flashing a flash device. In accordance with this prior art method, however, the image of an object to be photographed is watched through a view finder which remains in the same condition for the object distance from the infinity distance to the nearest distance. Therefore, at the time of close-up photography, the picture watched through the view finder comes to greatly deviate from a picture to be actually photographed thus presenting the problem of parallax.
Further, in cases where the camera of the kind permitting close-up photography is provided with a distance measuring device which automatically measures the object distance to detect the focal point of the photo-taking lens, since the distance measuring range increases in that instance in the direction of the nearest distance, the camera comes to necessitate use of either many distance measuring sensors or an extremely large distance measuring sensor. However, the use of many distance measuring sensors or a large distance measuring sensor results not only in a very expensive distance measuring device but also in a larger device which is detrimental to the reduction in size and cost of the camera desired.
Meanwhile, an attempt to shorten a base length and to obtain a wide distance measurable range with a smaller number of distance measuring sensors, for example, degrades the resolving power of the distance measuring device. Such an attempt thus eventuates in a camera which tends to make distance measurement errors.